tascam 688 wow and flutter

moogmymellotron

moogmymellotron

New member
Hello!

i hope someone can give me some insight on the tascam 688

i have a 688 that seems to be suffering from a condition i cant figure out. I recently replaced the capstan belt w a brand new one from tascam to cure that pesky stopping/starting situation. Thats gone but now i seem to have develop a really bad case of wow and fluttering. I cleaned the pinch roller but still...really unstable. any ideas of where i should be looking? im starting to think its the motor? also how does one go about calibrating the machine. thank you. id greatly appreciate any sort of response!


-Martin
 
Can you put up good closeup pic of the pinch roller? Is it tacky at all?

If there are any imperfections in the surface of that thing (and as the get old they loose resiliency and can get dented by the capstan when parked) it can wreak havoc with flutter...

If the belt was toast it is a reasonable assumption that the pinch roller needs replaced as well.
 
thanks for the heads up

the previous belt was just stretched out pretty badly. still played but was very intermittent.

ill try to post a pic of the roller within the next few hours. it doesnt seem shiny but it is a bit tough. is there anywhere i could find a new roller? ive tried tascam but theyre still backordered :/

thanks again!
 
I was gonna say that very same thing. If the belt was gone, all rubber components should be replaced, including the pinch roller and idler tires. If there's a control belt, then that should be done as well. What's the point of waiting for one to go after the next. Everything needs to be replaced.

Calibrating one of them things is pretty complex and would require a service manual, some test gear, including expensive alignment tapes and skills to do it right. I would leave it alone. The rubber components should be your main focus.
 
ive cleaned the roller a few days back and the problem seemed to worsen a bit. its usually pretty consistent now when it was come and go before.

also, ive noticed that recently upon playback the tape speed sometimes does not get up the right pitch, its always tuned down about a whole step. can this be attributed to the roller? or a motor?
 
moogmymellotron said:
ive cleaned the roller a few days back and the problem seemed to worsen a bit. its usually pretty consistent now when it was come and go before.

also, ive noticed that recently upon playback the tape speed sometimes does not get up the right pitch, its always tuned down about a whole step. can this be attributed to the roller? or a motor?
Click to expand...

How confident are you that you've replaced the belt properly?

About the speed change... If you're playing back tapes that you've recorded prior to the belt change then what you're hearing might be the material which was recorded at the wrong speed, played back at the correct speed (for the machine). See, if the belt was stretched out, you would have been recording at an erratic faster speed. Now, that you've changed belts, your previous stuff might be going slower now, due to the correction of the speed by way of a change of belts. Again, it's tough to judge based on your description.

Was the wow & flutter present prior to you doing the servicing? When exactly did wow & flutter start? Did it happen as soon as you changed the belt and / or clean the pinch roller.. when exactly? Did you use the machine recently, prior to servicing? When exactly did the pitch problems start? Also, with what and how did you clean the pinch roller?
 
im confident ive changed the belt properly since ive done this kind of thing before and especially to this machine.

the speed is a conclusion reached from recording a fresh set of tracks on a fresh tape. Not playing back existing material. I know the pitch changes because one minute its playing back in the key of A, next its G.

the wow and flutter was there prior but not as present. Seems like it started to increase once i wiped the roller w a qtip and some rubber cleaner. the roller was really dirty, i wiped it down clean w a qtip and it seemed to be fine for a while then the issue arose again.

the pitch problems were there from the beginning to intensified after cleaning the roller, im guessing the roller might be uneven. I just dont see how the roller could slow the playback of the music that drastically?
 
Sorry, have no clue but I do recall another Tascam product, the 238 I believe (but I could be wrong), having inherent speed issues. I'm going off the top of my head but it's usually a component which controls the motor speed rather than the motor. Whomever has more accurate info on this please contribute.
 
yea its a bit weird, its driving me mad. Today i used the machine for an easy 6 hrs and nothing was wrong, a few days ago, the machine couldnt hold pitch to save its life. :/

either way, im trying to find a pinch roller for it. tascam is backordered on them and i cant seem to find another suitable replacement for it. any ideas where i could find one? i remember reading somewhere that some of the other portastudios shared the same pinch roller? any help w this would be greatly appreciated!!!

thanks
 
A quick look at the 688 and 244 / 246 roller assembly confirms they're different. I'm not sure of the actual rubber puck but the assembly (the way it arrives from TEAC) is different.
 
Ugh...just re-reading this thread and realizing you're still having pitch issues after having changed the belt. I am, perhaps mistakenly, hoping the belt will be the cure for me.

Tascam was very vague with me about the availability of the 688 roller...saying something like "we don't have it, not sure if we have it on backorder or not...uhhh...ummm" or something like that.

Good luck with this. I'd love to hear an update if you come up with an alternative or have your roller refurbished...
 
thanks guys

ive kinda stayed clear from it for a few days. ive been tracking elsewhere :/

im going to continue w the machine hopefully figure something out for it. Im going to take it apart again, see if i might have overlooked something.

i usually call tascam weekly asking for the roller,and i always get the same response..."backordered"

i cant seem to find a decent alternative to substituting my roller either. 50 dollars to rebuild a roller is a bit much when i usually get my 16trk done for near the same.:/

i hear tascam still sells the motors for the unit?
 
Yes, I've used that stuff too with good success...won't fix a gooey roller or a roller that has truly hardened, but it will renue the glazed and surface hardened roller and help remove the stubborn stuff.

Yes-yes...ventilate or be :drunk:
 
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